docs: def _get_schema(modules):
      """Load the config schema for the provided modules.
  
      NOTE: this schema is intended to have 1-1 relationship with they keys in
      the default config and is used a means to verify valid overrides provided
      by the user.
  
      :param modules: stack modules config schema to lookup.
      :returns: modules default schema dictionary.
      """
      schema = os.path.join(os.path.dirname(__file__),
                            'defaults/%s.yaml.schema' % (modules))
      return yaml.safe_load(open(schema))